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Potentials of manufacture and repair of nickel base turbine components used in aero engines and power plants by laser metal deposition and laser drilling

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航空动力学报 2007年第5期22卷 739-748页

作者： I.Kelbassa K.Walther L.Trippe W.Meiners C.Over Chair of laser Technology RWTH Aachen Fraunhofer Institute for laser Technology Innoshape gmbh Steinbachstr.15 52074 AachenGermany

High pressure turbine(HPT) parts like blades and vanes with integrated cooling channels are challenging concerning overhaul and *** far damaged parts have to be replaced by the *** aim is to design and implement a refurbishment process chain to avoid scrapping of used *** process chain implies three different laser applications *** laser Forming(DLF),*** Metal Deposition(LMD) and *** Drilling(LD).The laser processing was extended in the last years towards application near materials like Nickel and Titanium base *** LMD and DLF the achieved results are investigated regarding macro and micro structure,hardness,defects(***,bonding defects,porosity) and contamination with atmospheric elements(e.g.O, N,C and H) are presented for Titanium alloys like Ti-6Al-4V,Ti-6246 and Ti-17 as well as for Nickel base alloys like Inconel 718 and Rene *** process parameters are presented with the achieved static(tensile) and dynamic mechanical properties(HCF) and compared to those of heat treated raw *** innovative solution(manufacturing case) is to fabricate the small and complex shaped geometrical elements by LMD and/or *** LMD these elements are built-up *** DLF the elements are manufactured separately in the DLF machine and connected by a subsequent joining technique with the large *** DLF small complex shaped parts like combustor swirlers,HPT blades and vanes with internal cooling channels are manufactured *** and DLF can be used in combination with subsequent *** on the application two different drilling techniques by dominant melt ejection-percussion drilling and trepanning-are classified and *** drilling techniques are exemplarily presented for stainless steel and nickel base alloys(diameter 0.2～0.6 mm,aspect ratiolaser radiation(Nd:YAG,1064 nm,0.5～1 ms).The experimental results of coaxial process control,metallog

关键词：激光打孔航空发动机镍基涡轮制造修复发电机金属沉积

Fast repetition rate fs pulsed lasers for advanced PLIM microscopy

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Journal of Innovative Optical Health Sciences 2019年第5期12卷 86-94页

作者： Sviatlana Kalinina Alexander Jelzow Tobias Plotzing Angelika Rück University of Ulm Core Facility Confocal and Multiphoton MicroscopyN24 Albert-Einstein-Allee 1189081 UlmGermany Becker&Hickl gmbh Nahmitzer Damm 3012277 BerlinGermany laser Quantum gmbh Max-Stromeyer-Str.11678467 KonstanzGermany

Simultaneous metabolic and oxygen imaging is promising to follow up therapy response,dis-ease development and to determine prognostic *** of metabolic coenzymes is now widely accepted to be the most reliable method to determine cellular ***,oxygen consumption has to be taken into account to understand treatment *** phosphorescence lifetimne of oxygen sensors is able to indicate local oxygen *** phosphorescence lifetime imaging(PLIM)dyes based on ruthenium(I)coordination com-plexes are useful,in detaill TLD1433 which possesses a variety of different triplet states,enables complex photochemistry and redox *** is usally reached by two photon exci-tation of the drug with a femtosecond(fs)pulsed Ti:Sapphire laser working at 80 MHz repe-tition rate and(time-correlated single photon counting)(TCSPC)detection *** interesting question was whether it is possible to follow up PLIM 1using faster repetition *** repetition rates could be advantageous for the induction of specific photochemical reactions because of similar light doses used normally in standard CW light *** this,a default 2p-FLIM-PLIM system was expanded by adding a second fs pulsed laser("helixx")which provides 50 fs pulses at a repetition rate of 250 MHz,more than 2.3 w average power and tunable from 720 nm to 920 *** laser beam was coupled into the AOM instead of the default 80 MHz *** demonstrated siuccessful applications of the 250 MHz laser for PLIM which correlates well with measurements done by excitation with the conventional 80MHx laser source.

关键词： Multiphoton microscopy axygen consumption phosphorescence lifetime microscopy fast repetition rate excitation short laser pulses Ru(I)complexes

Origin of potential errors in the quantitative determination of terahertz optical properties in time-domain terahertz spectroscopy

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Chinese Optics Letters 2015年第9期13卷 82-86页

作者：梁启军 Gregor Klatt Nico Krau? Oleksii Kukharenko Thomas Dekorsy Department of Physics and Center for Applied Photonics University of Konstanz laser Quantum gmbh Faculty of Physics National Taras Shevchenko University of Kyiv

We demonstrate theoretically and experimentally how changes of a terahertz （THz） beam induced by the sample affect the accuracy of the determination of THz dielectric properties in THz time-domain transmission spectros- copy （TDTS）. We apply a Gaussian beam and the ABCD matrix formalism to describe the propagation of the THz beam in a focused beam setup. The insertion of the sample induces a focus displacement which is absent in the reference t without a sample. We show how the focus displacement can be corrected. The THz optical properties after focus displacement correction reported in this Letter are in quantitative agreement with those obtained using collimated beam THz-TDTSinpreviouswork.

关键词： THz Origin of potential errors in the quantitative determination of terahertz optical properties in time-domain terahertz spectroscopy time

Targeting new ways for large-scale,high-speed surface functionalization using direct laser interference patterning in a roll-to-roll process

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International Journal of Extreme Manufacturing 2023年第3期5卷 569-583页

作者： Christoph Zwahr Nicolas Serey Lukas Nitschke Christian Bischoff Ulrich Radel Alexandra Meyer Penghui Zhu Wilhelm Pfleging laser Precision Manufacturing Fraunhofer Institute for Material and Beam Technology(IWS)DresdenGermany Topag lasertechnik gmbh DarmstadtGermany Institute of Manufacturing Science and Engineering Technical University DresdenDresdenGermany Institute for Applied Materials—Applied Materials Physics(IAM-AWP) Karlsruhe Institute of Technology(KIT)Eggenstein-LeopoldshafenGermany

Direct laser Interference Patterning(DLIP)is used to texture current collector foils in a roll-to-roll process using a high-power picosecond pulsed laser system operating at either fundamental wavelength of 1064 nm or 2nd harmonic of 532 *** raw beam having a diameter of 3 mm@1/e^(2) is shaped into an elongated top-hat intensity profile using a diffractive so-called FBS■-L element and cylindrical *** shaped beam is split into its diffraction orders,where the two first orders are parallelized and guided into a galvanometer *** deflected beams inside the scan head are recombined with an F-theta objective on the working position generating the interference *** DLIP spot has a line-like interference pattern with about 15μm spatial *** fluences of up to 8 J cm^(-2) were achieved using a maximum pulse energy of 0.6 ***,an in-house built roll-to-roll machine was *** this setup,aluminum and copper foil of 20μm and 9μm thickness,respectively,could be *** to current collector structuring coating of composite electrode material took *** case of lithium nickel manganese cobalt oxide(NMC 622)cathode deposited onto textured aluminum current collector,an increased specific discharge capacity could be achieved at a C-rate of 1℃.For the silicon/graphite anode material deposited onto textured copper current collector,an improved rate capability at all C-rates between C/10 and 5℃ was *** rate capability was increased up to 100%compared to reference *** C-rates between C/2 and 2℃,the specific discharge capacity was increased to 200 mAh g^(-1),while the reference electrodes with untextured current collector foils provided a specific discharge capacity of 100 m Ah g^(-1),showing the potential of the DLIP technology for cost-effective production of battery cells with increased cycle lifetime.

关键词： DLIP lithium-ion battery surface texturing copper aluminum

Multi-mW,few-cycle mid-infrared continuum spanning from 500 to 2250cm^(−1)

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Light(Science & Applications) 2017年第1期6卷 1-6页

作者： Jinwei Zhang Ka Fai Mak Nathalie Nagl Marcus Seidel Dominik Bauer Dirk Sutter Vladimir Pervak Ferenc Krausz Oleg Pronin Max-Planck-Institute of Quantum Optics Hans-Kopfermann-Str.1Garching 85748Germany Ludwig-Maximilians-University Munich Am Coulombwall 1Garching 85748Germany TRUMPF laser gmbh Aichhalder Straße 39Schramberg D-78713Germany

The demand for and usage of broadband coherent mid-infrared sources,such as those provided by synchrotron facilities,are *** most organic molecules exhibit characteristic vibrational modes in the wavelength range between 500 and 4000 cm^(−1),such broadband coherent sources enable micro-or even nano-spectroscopic applications at or below the diffraction limit with a high signal-to-noise ratio1–*** techniques have been applied in diverse fields ranging from life sciences,material analysis,and time-resolved *** we demonstrate a broadband,coherent and intrinsically carrier-envelope-phase-stable source with a spectrum spanning from 500 to 2250 cm^(−1)(−30 dB)at an average power of 24mW and a repetition rate of 77 *** performance is enabled by the first mode-locked thin-disk oscillator operating at 2μm wavelength,providing a tenfold increase in average power over femtosecond oscillators previously demonstrated in this wavelength ***-octave spectral coverage from this compact and power-scalable system opens up a range of time-and frequency-domain spectroscopic applications.

关键词： coherent repetition oscillator

The enhanced element enrichment in the supercritical states of granite–pegmatite systems

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Acta Geochimica 2019年第3期38卷 335-349页

作者： Rainer Thomas Paul Davidson Karen Appel Section 3.6.Chemistry and Physics of Earth Materials Helmholtz-Centre Potsdam German Research Centre for Geoscience – GFZ CODES Centre for Ore Deposit and Earth Sciences School of Natural Sciences University of Tasmania High Energy Density scientific instrument European X-Ray Free-Electron Laser Facility GmbH

In this paper, we show that supercritical fluids have a greater significance in the generation of pegmatites,and for ore-forming processes related to granites than is usually assumed. We show that the supercritical melt or fluid is a silicate phase in which volatiles; principally H_2O are completely miscible in all proportions at magmatic temperatures and pressures. This phase evolves from felsic melts and changes into hydrothermal fluids, and its unique properties are particularly important in sequestering and concentrating low abundance elements, such as metals. In our past research, we have focused on processes observed at upper crustal levels, however extensive work by us and other researchers have demonstrated that supercritical melt/fluids should be abundant in melting zones at deep-crustal levels too. We propose that these fluids may provide a connecting link between lower and upper crustal magmas,and a highly efficient transport mechanism for usually melt incompatible elements. In this paper, we explore the unique features of this fluid which allow the partitioning of variouselements and compounds, potentially up to extreme levels,and may explain various features both of mineralization and the magmas that produced them.

关键词： Granites Pegmatites Supercritical state Extreme element enrichment

The European X-ray Free-Electron laser: toward an ultra-bright, high repetition-rate x-ray source

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High Power laser Science and Engineering 2015年第3期3卷 13-19页

作者： M.Altarelli European XFEL gmbh Albert-Einstein-Ring

The status of the European X-ray Free-Electron laser(European XFEL), under construction near Hamburg, Germany, is described. The start of operations of the LCLS at SLAC and of SACLA in Japan has already produced impressive scientific results. The European XFEL facility is powered by a 17.5 Ge V superconducting linear accelerator that,compared to these two operating facilities, will generate two orders of magnitude more pulses per second, up to 27 *** can therefore support modes of operation switching the beam up to 30 times per second among three different experiments, providing each of them with thousands of pulses per second. The scientific possibilities opened up by these capabilities are briefly described, together with the current instrumental developments(in optics, detectors, lasers,etc.) that are necessary to implement this program.

关键词： femtosecond lasers and applications free-electron lasers and applications repetition frequency technology

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手动激光焊接系统开辟应用新领域

现代制造 2003年第12期 24-26页

作者： Christian Schmid Mobil laser Tec gmbh

利用带有传感器、单管驱动器和微型加工光学装置的手动激光焊接系统,对小批量、形状复杂的和大型工件进行焊接,比采用其他系统利用激光焊时有许多优点,而且速度快得多。

关键词：手动激光焊接系统传感器单管驱动器微型加工光学装置激光焊接机

Avalanche boron fusion by laser picosecond block ignition with magnetic trapping for clean and economic reactor

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High Power laser Science and Engineering 2016年第4期4卷 1-9页

作者： H.Hora G.Korn S.Eliezer N.Nissim P.Lalousis L.Giuffrida D.Margarone A.Picciotto G.H.Miley S.Moustaizis J.-M.Martinez-Val C.P.J.Barty G.J.Kirchhoff Department of Theoretical Physics University of New South Wales ELI-Beamline Project Inst. PhysicsASCRPALS Center Institute of Nuclear Fusion Polytechnic University of Madrid Soreq Research Center Institute of Electronic Structure and lasers FORTH Micro-Nano Facility Fondazione Bruno Kessler Department of Nuclear Plasma & Radiological Engineering University of Illinois Technical University Crete Laboratory of Matter Structure and Laser Physics Lawrence Livermore National Laboratory UJK Management gmbh

Measured highly elevated gains of proton–boron(HB11) fusion(Picciotto et al., Phys. Rev. X 4, 031030(2014))confirmed the exceptional avalanche reaction process(Lalousis et al., laser Part. Beams 32, 409(2014); Hora et al.,laser Part. Beams 33, 607(2015)) for the combination of the non-thermal block ignition using ultrahigh intensity laser pulses of picoseconds duration. The ultrahigh acceleration above 10^(20) cm s^(-2)for plasma blocks was theoretically and numerically predicted since 1978(Hora, Physics of laser Driven Plasmas(Wiley, 1981), pp. 178 and 179) and measured(Sauerbrey, Phys. Plasmas 3, 4712(1996)) in exact agreement(Hora et al., Phys. Plasmas 14, 072701(2007)) when the dominating force was overcoming thermal processes. This is based on Maxwell's stress tensor by the dielectric properties of plasma leading to the nonlinear(ponderomotive) force f_(NL)resulting in ultra-fast expanding plasma blocks by a dielectric explosion. Combining this with measured ultrahigh magnetic fields and the avalanche process opens an option for an environmentally absolute clean and economic boron fusion power reactor. This is supported also by other experiments with very high HB11 reactions under different conditions(Labaune et al., Nature Commun.4, 2506(2013)).

关键词： boron fusion energy dielectric nonlinear force explosion economic reactor environmentally clean energy picosecond-non-thermal plasma block ignition